Train routing and management

Been playing lots recently before a big train update coming trying to see the limits what update 3 trains can do and not.
= Allowing globally defined train station groups (like parking, refueling) that are allowed to be added to the schedule directly instead of clicking each station and making group all over again one by one for each relevant line. Defined group applies dynamically and changes are now easy.
= Allowing a train to be assigned to multiple schedules. Upon line completion train would look up all arrival conditions for assigned schedules and pick nearest available and complete that schedule to the end, and look up all assigned schedules arrivals again. Same as picking a station from a group now, but entire route for one cycle.
= Propagate whole station modules with first module selection as one whole, single product stations quite standard.
= Reversing trains with directional tracks don't work without station. But manually it works without any stations. Pathing? Fixable?

Adding one more:
= Adding the field for a station or a group to line schedules, that works similarly to refueling condition, let's say it got P button for condition instead of fuel level, and train goes to that station (group) if next schedule arrival condition is not met. Ideally this stations field would be out of the normal route schedule, and train could go park there at any point of the route to wait there for an arrival condition without skipping it. If track or station limit is blocking departure/arrival, train should always try to get back to normal schedule first, without needing to get to a waiting/parking destination to check for conditions again.